Linking metabolic networks with integrated white biotechnology process design

• Κύριος συγγραφέας: Μιχαηλίδη, Αικατερίνη
• Άλλοι συγγραφείς: Κούκος, Ιωάννης
• Μορφή: Thesis
• Γλώσσα: English
• Έκδοση: 2019
• Θέματα: Biomass; Fuel production; Βιομάζα; Παραγωγή ενέργειας; 662.88

For the sake of sustainability and environmental considerations, the chemical industry has turned to biomass-based production of fuels and chemical commodities. In view of that, significant research studies have been conducted on microorganisms producing high yields of the desirable end or intermediate products. Succinic acid has been identified by the U.S. Department of Energy as a top 12 target molecule due to the reactivity of the two carboxylic groups leading to versatile end-products and the cost-competitiveness of biotechnological over petrochemical production. Over the past years, there is an increasingly number of studies concerning microorganisms producing succinic acid, some of which are Basfia succiniciproducens, Actinobacillus succinogenes and Mannheimia succiniciproducens. The aforementioned bacteria produce high yields of succinic acid since it is a major metabolic intermediate, as reflected by their names. In recent years, optimization has been employed to predict the distribution of carbon flux in the metabolism of a bacterium. In this thesis, the specifications of each microorganism, the set of reactions implied and the results regarding the polyhedra of the feasible regions provided by metabolic flux analysis are studied. The developed model is employed to support experimental data and its validity is assessed. A mathematical model for designing and optimizing the biotransformation (upstream) section of biotechnological processes is presented. The model has been augmented by equations for the estimation of the equipment cost derived from a recent publication by the US National Renewable Energy Laboratory. The processes of the downstream section for the recovery of succinic acid are then presented, along with a financial analysis of the case study for the biobased production of succinic acid. A key step in the decision making in the design of a fermentation process is to choose an appropriate strain and/or improve it, since the product of interest is primarily determined by the properties of the microorganism. Consequently, a quantitative approach in which basic principles of the biosciences is combined with core disciplines from the engineering fields will indicate the best design of any bioprocess. The novelty of this study is that it incorporates significant details of the bioprocess design and also use is made of a relatively accurate model that simulates the metabolic pathways of microorganisms. Therefore, the model provides a linkage between the metabolism of bacteria and the operation and design of white biotechnology processes.